Council communism or councilism is a current of left-communist thought that emerged in the 1920s. Inspired by the November Revolution, council communism was opposed to state socialism and advocated workers' councils and council democracy. Councilism is also opposed to Leninism and Stalinism. It was strongest in Germany and the Netherlands during the 1920s.

Council communism emerged in the years after 1918, as some communists in Germany and the Netherlands concluded that the Russian Revolution had led to power being concentrated in the hands of a new political elite. Its most prominent early proponents were the German educator Otto Rühle, the Dutch astronomer Anton Pannekoek, and the Dutch poet Herman Gorter. They were initially enthusiastic supporters of the Bolsheviks and the Russian Revolution. In 1918, Gorter said that the Bolshevik leader Vladimir Lenin "stands out above all other leaders of the Proletariat" and that Karl Marx was Lenin's sole peer. In 1919, Pannekoek wrote that "in Russia communism has been put into practice for two years now".

When the Communist Party of Germany (KPD) was formed in December 1918, a majority in the party was opposed to electoral politics and trade unionism. These positions placed it to the left of Bolshevik orthodoxy. In 1919, the Communist International (Comintern) was formed to promote Bolshevik policies internationally. In October 1919, Paul Levi, the head of the KPD leadership, pushed through a new party line that followed the Comintern's policies. This line called for participation in parliamentary elections and fighting for control of established labor unions. In effect, this forced the left majority out of the party and about half of its 100,000 members left. In April 1920, the left formed the Communist Workers' Party of Germany (KAPD) with an initial membership of about 38,000. The move was partly motivated by the fact that the left perceived the KPD's reaction to the Kapp Putsch as weak. The same year, the General Workers' Union of Germany (AAUD) was formed as a revolutionary labor union partly modeled on the American Industrial Workers of the World (IWW). It was seen by some as the union federation affiliate of the KAPD. At its peak in August 1920, the KAPD had around 40,000 members, with another 200,000 people organized in the AAUD.

In 1918, Gorter wrote the pamphlet The World Revolution pointing to differences between the situations in Russia and Western Europe. Pannekoek asserted in World Revolution and Communist Tactics, a pamphlet he published in 1920, that communist tactics in Western Europe were necessarily different from those in Russia. He argued that in Western Europe the bourgeoisie was more established and experienced and that as a result class struggle must oppose bourgeois institutions such as parliaments and trade unions. He emphasized the importance of class consciousness among the masses and deemed the vanguard party model advocated by the Bolsheviks a potential obstacle to revolution.

Immediately after the KAPD's formation, it sought admission to the Comintern. At the Second World Congress of the Comintern in 1920, the Comintern leaders Lenin, Leon Trotsky, and Grigory Zinoviev unanimously rejected the KAPD's positions. An open letter by the Comintern's executive committee informed the KAPD that the Comintern fully supported the KPD in its dispute with the left. Some KAPD delegates left the congress early in protest. Lenin criticized the KAPD, Pannekoek, and other left groups in the 1920 pamphlet "Left-Wing" Communism: An Infantile Disorder, accusing them of spreading confusion. He claimed that a refusal to work in parliaments and labor unions would leave workers under the influence of reactionary leaders. He conceded that there were considerable differences between Russia and the more advanced countries in Western Europe, but held that "it is the Russian model that reveals to all countries something – and something highly significant – of their near and inevitable future" and that certain features of the Russian Revolution were universally valid. Gorter took on the task of answering Lenin. His Open Letter to Comrade Lenin reiterated the argument that the differences in the class structure between East and West necessitated differences in communist tactics.

Despite this dispute, the KAPD, and other similar groups, initially sought to change the international communist movement from within. At the Third World Congress of the Comintern in 1921, the KAPD failed to rally a left opposition and therefore withdrew from the International. The council communist critique of Bolshevism became more fundamental. Council communists concluded that the Bolsheviks were not in fact building socialism. In 1921, Pannekoek argued that the Russian Revolution was but a bourgeois revolution like the French Revolution. Gorter characterized it as initially a dual revolution, a working-class revolution against capitalism and a capitalist revolution against feudalism, but argued that this dualism was resolved with the New Economic Policy of 1921 and that Soviet Russia had become unambiguously a capitalist state.

By 1921, council communism had broken with the official communist movement and formed a distinct current, according to the historian Marcel van der Linden. The term council communism itself was first used by Franz Pfemfert in 1921. Many authors agree with van der Linden in dating the emergence of council communism to the early 1920s, but others, like Philippe Bourrinet and John Gerber, refer to the tendency as the Dutch–German form of left communism during this period and date the advent of council communism to the 1930s. According to van der Linden, council communism was defined by five basic principles:

The German and Dutch left was part of a broader left communist movement that pushed back against the imposition of the Bolshevik model on Western Europe. In Vienna, Georg Lukács emphasized the importance of the spontaneity of the working class. In Italy, Amadeo Bordiga was opposed to electoral politics, but had little regard for councils as the basis for a reorganization of society and advocated vanguard parties as Lenin did. In Russia, the Workers' Opposition criticized the bureaucratization of working-class organizations and sympathized with the KAPD.